RSQ3 Serpentine Belt Issues: Tensioner Failure Signs

Had the same belt squeal issue on my 2017 Audi RS3. The symptoms matched exactly, inconsistent belt movement and that distinctive noise during engine operation. The root cause was indeed a failing belt tensioner. Left unchecked, this can lead to serious engine performance problems and potentially damage multiple components driven by the serpentine belt including the alternator, power steering pump, and air conditioning compressor. First step is checking the tensioner pulley for smooth rotation, any wobble indicates wear. In my case, both the tensioner and timing belt needed replacement as they had worn unevenly due to the faulty tensioner. This became a critical repair as the belt could have snapped, potentially causing significant engine damage. The repair involved: Removing the serpentine belt, Replacing the belt tensioner assembly, Installing a new serpentine belt, Adjusting proper tension, Testing under various engine speeds This is not a DIY job unless you have proper tools and expertise. The tensioner system is complex and critical for proper engine operation. Would recommend finding a certified Audi specialist who can properly diagnose and repair the system.

Thanks for sharing your experience. The symptoms you described with the belt tensioner match what I dealt with too. After seeing your post, I did end up taking my RSQ3 to an Audi specialist for proper automobile maintenance. They confirmed the diagnosis and fixed the belt squeal issue. The engine noise completely disappeared after the repair. Just curious, do you remember roughly what you paid for the full service? Also, have you noticed any other issues coming up since the belt tensioner replacement?

After my tensioner pulley repair a few months ago, everything has been running perfectly smooth with no recurring belt squeal or other engine performance issues. The total repair cost for my RS3 was 455 Euro which covered the full belt tensioner replacement and labor. This included a thorough inspection of the serpentine belt system and idler pulley to ensure proper operation. Regular automobile maintenance checks since then have shown no additional problems. The new tensioner keeps the belt tracking properly and eliminated all the concerning noises. Having a certified specialist handle the repair was definitely worth the investment to prevent more serious engine complications down the road. Make sure to keep an eye on the belt tension during future service intervals, but with a new tensioner installed, you should be good for many kilometers of trouble-free operation.

Thanks for the input. I wanted to share how it all worked out after getting the repair done last week. The specialist shop fixed everything in about 4 hours. Total cost came to 480 Euro for the tensioner pulley replacement and labor, which seemed fair given the work involved. The serpentine belt is running perfectly now, no more squealing or slipping issues. The automobile maintenance technician showed me the old tensioner which was pretty worn out. They also did a complete check of the timing belt while everything was apart, which gave me extra peace of mind. Really glad I didn't try to keep driving with the faulty tensioner. The mechanic explained how it could have led to complete belt failure and potentially serious engine damage. The engine runs so much smoother now, definitely worth getting it properly fixed by professionals. For anyone else hearing weird belt noises, don't wait like I initially did. Get it checked out before it becomes a bigger problem.